#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
queue <int> q;
vector <int> v[100001];
int n,m,i,nr,x,y,viz[100001],nod,j;
int main()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nr++;
            viz[i]=1;
            q.push(i);
            while(!q.empty())
            {
                nod=q.front();
                q.pop();
                for(j=0;j<v[nod].size();j++)
                {
                    if(viz[v[nod][j]]==0)
                    {
                        q.push(v[nod][j]);
                        viz[v[nod][j]]=1;
                    }
                }
            }
        }
    }
    fout<<nr;
    return 0;
}